It used to be that "convertible PC" could mean only one thing: a laptop whose display swiveled around, folding down into tablet mode. Now that Windows 8 is here, though, the category has become a bit muddied. How else to describe our recent collection of reviews? In just the past few weeks alone, we've tested a laptop whose screen folds all the way back, an Ultrabook whose display flips inside the hinge and yet another with a slide-out keyboard. Anything goes -- at least until consumers decide which form factor they like best.

But when Lenovo calls its new ThinkPad Twist a convertible, you can rest assured it's using the old-school definition. As the name implies, it has a rotating screen that allows it to be used as a 12-inch slate. And, like all the business-friendly ThinkPads that came before it, it sports a well-engineered keyboard, a secondary set of touch buttons and, of course, that signature red pointing stick. Now, though, it runs a much more finger-friendly OS, and has a touchpad that can support all the new gestures in Windows 8. It's one of several new touch-capable notebooks from Lenovo, but it's the only one geared toward business users. So is this worth the upgrade from an older ThinkPad? And is it a better buy than Lenovo's other Win 8 convertible, the IdeaPad Yoga 13? Read on to find out.